how do i get rid of my toxic way of thinking?

uh so TW//MENTIONS OF MENTAL ILLNESS

i've always noticed this and idk how to fix it but i try so hard to be the "not like other girls" stereotype and convince myself i'm okay and faking. i also have a harmful thoughts about mental illness and suicide which luckily, i'm not paying attention to very often. i basically try so hard to mask myself as an uwu depressed girl and i feel like i end up harming others in the process. i don't even know if my personality is real or not. most of my interests are similar to those who are "not like other girls". i actually convince myself i'm faking and just hate myself even more. when i was in 4th or 5th grade, i used to say things like "i hate myself" or "i'm so bad, i probably would become worse when i'm older" as a joke (but also truthful). i also had some weird thoughts about wanting sleeping forever when i was sad? is that my way of "coping"? i always knew to some extent when i was younger, that what i said was true.. i always thought people who said "joking is my way of coping" were kinda harmful (hahaha how funny i became one of the people who say that). i also question my gender sometimes because i hate my body so much (idk why i hate it so much i'm fine with being fat).

about my very insensitive thoughts about mental illness, uhh i'm really sorry but whenever i see those posts where they say stuff like "why don't you kill yourself if you're so depressed" part of me agrees and i wish i could just stop. i also pretend whatever my psychiatrist says isn't true and i'm just okay and i don't need to cooperate with anyone because in reality i am completely fine. whenever i get a suicidal or hopeless thoughts i end up thinking "uwu i'm so depressed :((" to mock myself. i also tell myself there's no reason for me to be this way (because there actually is no reason idk why i'm like this) my life is so good (i think?). i was spoiled a bit in my childhood so i'm confused as to how i ended up like this but i do acknowledge that i was definitely not okay before i acknowledged the fact that i am mentally ill. i also think that people who are mentally ill are selfish, weak and "crazy". this is only due to my mother's influence on me though so i probably wouldn't keep this mindset.

i'm sorry that i always use mangago as a venting platform, i see a lot of people here who are vocal about being mentally ill so i guess i'm kinda comfortable here. so how do i stop myself from being like this? also how do i find out the reason why i'm mentally ill? i'm sorry i keep referring it to "mentally ill" i don't mean to offend anyone. how do i stop myself from trying so hard to be like the "i'm not like other girls" girl?